243217920 has 160 divisors (see below), whose sum is σ = 848517120. Its totient is φ = 58941440.

The previous prime is 243217907. The next prime is 243217921. The reversal of 243217920 is 29712342.

243217920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243217921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83041 + ... + 85919.

It is an arithmetic number, because the mean of its divisors is an integer number (5303232).

Almost surely, 2^243217920 is an apocalyptic number.

243217920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 243217920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (424258560).

243217920 is an abundant number, since it is smaller than the sum of its proper divisors (605299200).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

243217920 is a wasteful number, since it uses less digits than its factorization.

243217920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2916 (or 2900 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 243217920 is about 15595.4454889881. The cubic root of 243217920 is about 624.2116310438.

The spelling of 243217920 in words is "two hundred forty-three million, two hundred seventeen thousand, nine hundred twenty".